The image is of a micro-Pulsed Plasma Thruster after being fired over 35,000 times. The thruster is made up of concentric rings of Copper and Teflon. When the thruster fires an electric arc forms over the surface, ablating and ionizing the Teflon propellant.

The photograph highlights soot formation and transport in a laminar, bluff-body-stabilized flame. The flame is stabilized on a centerbody where ethylene fuel flows from a jet at the center, and reacts with the air that flows around the edge of the centerbody.